The only thing I've heard of is a new style of device which is "mechanical and electric, but expensive". I don't know any more about it.
The Bib / SS HD is the best combo for me. It's allowed me to feel in control of gains and taken the magic out of it. I now feel confident about it, in fact I'm a bit giddy about it anymore. I feel like I will hit my goal of another inch within the next 6 to 9 months.
What I do is hang what I can for one set and then tape up my glans and pop on the HD for at least an hour, usually much more. Also to set in fatigue (in order to ride it) I have done two different things in the past 4 months:
(Let me first say that I only need to do this if I've taken a break for some reason, usually travel). I either hang a marathon day with the Bib (lower than my max weight but many sets, or I strap on the HD and wear it for 8 to 12 hours. I can then ride this fatigue for several weeks by using the bib/HD combo I mentioned above.
I usually hang 3 times a day (morning, afternoon and night) which are all followed by at least an hour of SS HD.